Combine flour, sugar, baking powder and salt in a bowl. Whisk eggs, 3 tbsp butter and buttermilk in another bowl. Whisk wet ingredients into dry ingredients until just combined. Cover batter and let rest overnight in the refrigerator. Heat a large greased griddle or large nonstick skillet over medium heat. Add milk to batter until it reaches desired consistency; the more milk, the thinner and more delicate the pancakes. Working in batches of three pancakes, spoon batter onto griddle or skillet. Cook until surface of pancake is covered with bubbles, for 2 to 3 minutes. Flip and cook the other side until golden, 2 to 3 minutes. Drizzle warmed maple syrup over pancakes; serve. Yum!